The present invention relates generally to automated storage libraries having robotic accessors or mechanisms that manipulate media cartridges and, more particularly, to a synchronous mounting and dismounting method and system for a storage library having multiple robotic mechanisms.
Existing automated storage libraries are capable of storing and retrieving large quantities of information stored on media cartridges. This is accomplished by the use of a large number of cartridge storage cells, each of which houses a media cartridge, that are housed within an enclosure. Such storage libraries use a robotic mechanism or picker to move the media cartridges between their media cartridge storage cells and media cartridge players. For example, to retrieve information stored on a selected media cartridge, a robotic mechanism moves to a location opposite the media cartridge storage cell that houses the selected media cartridge. An end effector of the robotic mechanism then grasps the media cartridge and extracts it from the media cartridge storage cell to a media drive where the end effector loads the media cartridge into the drive.
A typical storage library includes tracks or rails laid out throughout the storage library. Robotic mechanisms are mounted to the tracks to move throughout the storage library to access the cartridges and the drives. A problem occurs when two robotic mechanisms contend for access to the same resources such as a drive. For instance, one robotic mechanism may be waiting to load or mount a drive while another robotic mechanism is unloading or dismounting the same drive. Typical storage libraries do not unlink the mounting operation from the dismounting operation. A method and system for a storage library having multiple mechanisms which makes the mounting functions independent of the dismounting functions would improve the mounting time rate and the overall throughput of the storage library.
Accordingly, it is an object of the present invention to provide a synchronous mounting and dismounting method and system for a storage library having robotic mechanisms.
It is another object of the present invention to provide a method and system for a storage library having robotic mechanisms which make the mount functions performed by the robotic mechanisms to be independent of the dismount functions performed by the robotic mechanisms.
It is a further object of the present invention to provide a method and system for a storage library having robotic mechanisms which make the robotic mechanisms move around the storage library along a looping travel path for enabling the dismounting of media cartridges from locations within the storage library to be done independently as a background function to the mounting of media cartridges to other locations within the storage library.
It is still another object of the present invention to provide a method and system for a storage library having robotic mechanisms which control the robotic mechanisms to move around the storage library along a looping travel path in the same direction such that there is no contention between the robotic mechanisms during mounting and dismounting of different media cartridges from locations within the storage library.
It is still a further object of the present invention to provide a method and system for a storage library having robotic mechanisms which control the robotic mechanisms to move around the storage library along a looping travel path in the same direction such that the robotic mechanisms chase each other around the storage library to prevent contention between the robotic mechanisms for resources of the storage library.
In carrying out the above objects and other objects, the present invention provides an automated storage library for the storage and retrieval of cartridges and an associated method. The storage library includes a frame having a plurality of cartridge storage cells for storing cartridges and at least one cartridge player for playing a cartridge. At least two robotic mechanisms are each movable within the frame to mount a cartridge from a cartridge storage cell into the cartridge player and to dismount a cartridge from the cartridge player into a cartridge storage cell. A controller controls the robotic mechanisms to move in a first direction around the frame along a closed loop travel path such that one of the robotic mechanisms dismounts a cartridge from the cartridge player into a cartridge storage cell while another one of the robotic mechanism mounts another cartridge from another cartridge storage cell into the cartridge player. The controller controls the robotic mechanisms such that the one of the robotic mechanisms unloads the cartridge from the cartridge player prior to the other one of the robotic mechanisms loading the other cartridge into the cartridge player.
Preferably, the controller controls the robotic mechanisms to traverse around the frame along the first direction in the closed loop without reversing the course of movement. The frame includes a closed loop concentric row of cartridge storage cells and a cartridge player. The controller controls the robotic mechanisms to move in the first direction around the closed loop concentric row of cartridge storage cells and the cartridge player. The controller controls the robotic mechanisms to move in the first direction around the frame along the closed loop such that the robotic mechanisms avoid contention with access to the cartridge storage cells and the cartridge player.
Preferably, the controller provides a dismount drive command to a first robotic mechanism and a mount drive command to a second robotic mechanism for the first robotic mechanism to dismount the first cartridge while the second robotic mechanism mounts the second cartridge. The controller then provides a mount drive command to the first robotic mechanism and a dismount drive command to the second robotic mechanism for the first robotic mechanism to mount a third cartridge while the second robotic mechanism dismounts the second cartridge after the first robotic mechanism has dismounted the first cartridge and the second robotic mechanism has mounted the second cartridge. The controller then provides a dismount drive command to the first robotic mechanism and a mount drive command to the second robotic mechanism for the first robotic mechanism to dismount the third cartridge while the second robotic mechanism mounts a fourth cartridge.
The first robotic mechanism in response to the dismount drive command moves in the first direction along the closed loop to the cartridge player, removes the first cartridge from the cartridge player, moves in the first direction along the closed loop from the cartridge player to the first cartridge storage cell which is to house the first cartridge, and then loads the first cartridge into the first cartridge storage cell.
The second robotic mechanism in response to the mount drive command moves in the first direction along the closed loop to the second cartridge storage cell housing the second cartridge, removes the second cartridge from the second cartridge storage cell, moves in the first direction along the closed loop from the second cartridge storage cell to the cartridge player, and then loads the second cartridge into the cartridge player.
The frame may be a round frame, a rectangular frame, or the like. The closed loop may be a closed circular loop, a closed rectangular loop, a closed serpentine loop, or the like.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the present invention when taken in connection with the accompanying drawings.